Carburetor



'Dec', 29 ;1925

CARBUBETOR G. M. HOLLEY Filed July 19, 1922- 2 Sheets-Sheet 1 i I l /4////// //A Geo. M HoLLeY INVENTOR.

Patent ecl' Dec, 2 9, 19 325; 'UNITED STATES' Z'o all wlbm it may camera: Be it known that I, GEORGE M. HOLLEY, a' citizen of the United Statesflesiding at 2150 i Burns Ave., Detroit, in the county of Wayne '5 and State of Michigan, have invented certain newand useful Im rovements in Carburet- 4 "ors,-of which the fo lowing is a specification.

' This invention relates 'to an improvement n carburetors intended for use with automobile engines of the internal combustion type.

This' invention relates speeifically to that 4 type 'of carburetorcomtnonly known as a va porizer in' which exhaust leat is applied to the priinary air and fuel and in which the 1 heated'rich n'ixture thereby made is' diluted with a much greater Volume of comparetively cold air admitted through a passage regulated b an auxiliary air valve.

The specfic objects sought in 'this inven- 9' .tion` are as follows:

v 1 Means for. controllingthe nixture'temperature'so as to prevent overheating of the fueL i 2. Improved atomization-of the fuel.

h fil igure 1 shows the details of Construction `int cross 'sectional elevation, on plane 1-1 of `Figure;2. 7

. 'Iigure 2 shows the carburetor in cross sectio'nalv elevation, taken on the plane 2-2 of Figure 1 'and the primer incor porated with the carburetor, on the plane 2 of Figure' 1.

'Figure 3 shows a cross section through the primer, also taken on the plane 2-2 of Figposition;

. Figure .4 shows a cross section, on the 'plane 4-4 of Figure 2, and showsanoth'er detail of the primer in elcvation.

ure'1, showing the primer in its Operating 40 .-Oa1'burctor.-In Figur-os 1 and 2, A is the exhaust manifold of an internal coiibustion engine of the automobile type having a pluralty of 'cylinders X isa dep'endant chamber leading out of the main exhaust passage and providing a dead space in which the circulation of the exhaust gases is modified r id greatly reduced. B is an inlet manifold,

- ;preferablv arranged above the exhaust manifold A. C is a. fioat chamber, the flow of fuel .50 fromwhich is controlled by the orifice D and its' cooperating valve. F (Figura 2) is the .primary air heater located in the exhaust manifold and extending' down through the dep'endant chamber X. G is a small Venturi tube forming the primary mixing chamber.

-' L is the fuel passageleadng to the throat of CARBURTOR.

Application filed Iu 19, 1922. Serial- Ni). 576,oe. p

'PATENT -OFFICE.

I GEORGE M. EOLLEY, OF DETROT, MIC HIGAN.

.the said Veituri tube and connected the restricted outlet D.- J is the pipeor passage through which the mixture flows from the pnary mixing chamber G to the secondary `mxing chamber K, 'which is-. also for nedn the shape of a venturi. v

The valv'e H is 'a cold air entrance for adnitting air from the atmosphere te mix with and model-ate the temperature of the heated ar drawn down through F and thereby supply to the prmary mixing chamber Ur air of a regulated temperature, the temperature 'being determined by the position oftle valve H, which is provided with springdea tent' h adapted to retain the valve' in`any given position.

E is a helical strip of metal inserted in the tube F for the purpose of increasing the effectiveness of the tube J. N is a similar twisted strip of metal located in the air and fuel heating tube J for a corresponding pul"- -pose; The strip N is removable for the purpose of cleaning the tube J.

0 is the cold air entrance to the secondarv nixing chamber K. 'This air entrance is chamber Kthrough the boss of the choke valve P, as shown in Fig res2, 3, and-4.- The fuel nozzle R is normally' submerged and diseharges into ,the well U which is vented to the atmosphere through the pening T. This well known arrangement' rovides an initial starting charge followe b aTich mixture formed from the air enterng at-T inixing with the fuel aspirated at R the mixture passing through S..

This richmikture enters the casting' containing the 'secondary mixing V ehamber through the passage comprising several arts, the part 2 communicating with the tu S.

This passage Z; leads through another pa ssage Y t the valve Q, (Figure 4), which is integral with the valve P. From Q there is a passage V-leading to the secondary mixin chamber K. ,The valve Q, being integral witthe valve Pit follows that when the valve P becomes excessive,

. mixture 'reduced by O ,mitting cold air which is taken in through G, up J, and so' into the secondary nixing is moved'the valve Qis also moved and the valve Q is arranged so that fuel may flow from Y to Z when, and only when, the valve P is closed, which is, of course, the starting %osition of the choke valve P. The primer S, T, U is therefore only operative when the choke valve P is closed.

operation-Ju starting the engine the mixture throttle vaive W is partially opened 4 and the choke Valve, or strangling Shutter as it is frequently called, P in the main or secondary air entrance 0 is completely closed, the valye, Q being thereby opened so that the pipe S is in free' communication, through Z and Y, with the passage V and so with the Venturi throat K- of the secondary mixing chamber. Fuel in the well U is therefore swept out by the air entering at T and a rich mixture is subsequently discharged through the tube S by reason of the fuel aspirated from the nozzle R. This rich mixture, together with the priming fuel contained in the well U, facilitates starting.

Meanwhile, air is entering down F, through the primary mixing chamber G, where fuel is aspirated out of L, andmixed with the air flowing up J, and a rich mixture is thus drawn up J and flows into the engine along with the primingcharge issuing through V into the secondary mixing chamber K.

Nhen the engine begins to fire the exhaust gases quickly heat up the tubes F and J as they are made of thin-walled metal' tubes, and in a comparatively short period of time (15 seconds), it is possible to open the valve P cutting off the primer R, S, T, U, and to admit cold air past the valve N into the secondary mixture chamber K. Thereafter fue). is supplied solely from the passage L deliyering to the threat of'the primary mixing chamber G.

In normal operation the primary air is heated in the tube F, fuel issues from L into the primary mixing chamber G, the rich fiows through J where it is further heated, and a heatedrich mixture issues into the secondary miting chamber K. The loeation of the tube J in the dependantchamber X ensures that the fuel is subjected to a grndually increasing heating etfect.`

in the event that the mixture temperature the mixture temperature in the primary mixing chamber G is readily opening the valve H, thereby adchamber K. This control is intended chiefiy for use in hot weather.

The advantages of this Construction is that one of the greatest diflculties experienced with carburetors having separate primary and secondary mixing chambers is overcome. 4 Ths dfficulty s n starting, due to the consderable distance separatmg the primary mixing chamber from the secondary mixng chamber, and 'also because the primary mixing chamber is necessarily large enough to carry the total requiremcnts of the' engine, hence it is larger than is desh'- able when Starting. small independent prining device R, S, T, U this difficulty is largely overcome. in order to clean the tube J it is necessary to remove the helix containcd therein. To do this it is necessary to disassemble the carburetor, separating the casting containing the float chamber C from the exhaust manifold A. At the Same time it would render the twisted strip E accessible.

What I claim is-- 1. In combination with an internal conbustion engine, an exhaust pipe, a carburetor comprising primary and secondary mixing chambers, a fuel nozzle diseharging into said rmary mixing chamber, an air passageeading to said primary nixin chamber in heat 'conducting relationshp with said exhaust pipe, a cold air entrance located between said air passage and said primary mixin chamber, means for controlling said air entrance forregulating the temperature in said rimary mixing chamber, a passage connectng said primary nixing chamber to Saidsecondary mixing chamber, said assage being in heat conduct` ing relationshp with said exhaust ipe, a

By the provision ot' a seeondary air entrance leading to said secondary mixing chamber to form therein an explosive mixture for said internal combustion engine.

2. In combinat ion with an internal combustion engine, :in exhaust pipe, a. carburetor comprising primary andsecondary mixing chambers, said primary mixing chamber, an air passage leading to said rimary mixing chamber in heat conduet ng relationship with said exh'aust pipe, a cold air entrance located between said air passage and said primary mixing temperature in said primary mxing chamber, a passage connecting said rimary mixchamber to said secon ary mixing chamber, a secondary air entrance leading to said seeondary mixing chamberto form therein an explosive mixture for said internal c'ombustion engine.

In testimon'y whereof I aix my signature.

GEO. MQHOLLEY. l

a fuel nozzle discharging into 

